Added GRBlockCounter class, which tracks the number of times blocks
have been visited in a path. Added GRBlockCounter as an item to be
enqueued to the worklist.
Modified "ProcessBranch" in GRConstants to prune branches with symbolic
conditions that have been already taken.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@47010 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/Analysis/GRBlockCounter.cpp b/Analysis/GRBlockCounter.cpp
new file mode 100644
index 0000000..def87c2
--- /dev/null
+++ b/Analysis/GRBlockCounter.cpp
@@ -0,0 +1,54 @@
+//==- GRBlockCounter.h - ADT for counting block visits -------------*- C++ -*-//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines GRBlockCounter, an abstract data type used to count
+// the number of times a given block has been visited along a path
+// analyzed by GREngine.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Analysis/PathSensitive/GRBlockCounter.h"
+#include "llvm/ADT/ImmutableMap.h"
+
+using namespace clang;
+
+typedef llvm::ImmutableMap<unsigned,unsigned> CountMap;
+
+static inline CountMap GetMap(void* D) {
+ return CountMap(static_cast<CountMap::TreeTy*>(D));
+}
+
+static inline CountMap::Factory& GetFactory(void* F) {
+ return *static_cast<CountMap::Factory*>(F);
+}
+
+unsigned GRBlockCounter::getNumVisited(unsigned BlockID) const {
+ CountMap M = GetMap(Data);
+ CountMap::TreeTy* T = M.SlimFind(BlockID);
+ return T ? T->getValue().second : 0;
+}
+
+GRBlockCounter::Factory::Factory(llvm::BumpPtrAllocator& Alloc) {
+ F = new CountMap::Factory(Alloc);
+}
+
+GRBlockCounter::Factory::~Factory() {
+ delete static_cast<CountMap*>(F);
+}
+
+GRBlockCounter
+GRBlockCounter::Factory::IncrementCount(GRBlockCounter BC, unsigned BlockID) {
+ return GRBlockCounter(GetFactory(F).Add(GetMap(BC.Data), BlockID,
+ BC.getNumVisited(BlockID)+1).getRoot());
+}
+
+GRBlockCounter
+GRBlockCounter::Factory::GetEmptyCounter() {
+ return GRBlockCounter(GetFactory(F).GetEmptyMap().getRoot());
+}
diff --git a/Analysis/GRConstants.cpp b/Analysis/GRConstants.cpp
index 4ae9077..8b94aaa 100644
--- a/Analysis/GRConstants.cpp
+++ b/Analysis/GRConstants.cpp
@@ -375,23 +375,45 @@
}
}
- // Process the true branch.
- bool isFeasible = true;
+ // Get the current block counter.
+ GRBlockCounter BC = builder.getBlockCounter();
+
+ unsigned NumVisited = BC.getNumVisited(builder.getTargetBlock(true)->getBlockID());
- StateTy St = Assume(PrevState, V, true, isFeasible);
+ if (isa<nonlval::ConcreteInt>(V) ||
+ BC.getNumVisited(builder.getTargetBlock(true)->getBlockID()) < 1) {
+
+ // Process the true branch.
- if (isFeasible)
- builder.generateNode(St, true);
- else {
- builder.markInfeasible(true);
- isFeasible = true;
+ bool isFeasible = true;
+
+ StateTy St = Assume(PrevState, V, true, isFeasible);
+
+ if (isFeasible)
+ builder.generateNode(St, true);
+ else
+ builder.markInfeasible(true);
}
+ else
+ builder.markInfeasible(true);
- // Process the false branch.
- St = Assume(PrevState, V, false, isFeasible);
+ NumVisited = BC.getNumVisited(builder.getTargetBlock(true)->getBlockID());
+
- if (isFeasible)
- builder.generateNode(St, false);
+ if (isa<nonlval::ConcreteInt>(V) ||
+ BC.getNumVisited(builder.getTargetBlock(false)->getBlockID()) < 1) {
+
+ // Process the false branch.
+
+ bool isFeasible = false;
+
+ StateTy St = Assume(PrevState, V, false, isFeasible);
+
+ if (isFeasible)
+ builder.generateNode(St, false);
+ else
+ builder.markInfeasible(false);
+ }
else
builder.markInfeasible(false);
}
diff --git a/Analysis/GREngine.cpp b/Analysis/GREngine.cpp
index e3b238a..9858f24 100644
--- a/Analysis/GREngine.cpp
+++ b/Analysis/GREngine.cpp
@@ -71,6 +71,9 @@
// starting location in the function.
BlockEdge StartLoc(getCFG(), Entry, Succ);
+ // Set the current block counter to being empty.
+ WList->setBlockCounter(BCounterFactory.GetEmptyCounter());
+
// Generate the root.
GenerateNode(StartLoc, getInitialState());
}
@@ -78,6 +81,11 @@
while (Steps && WList->hasWork()) {
--Steps;
const GRWorkListUnit& WU = WList->Dequeue();
+
+ // Set the current block counter.
+ WList->setBlockCounter(WU.getBlockCounter());
+
+ // Retrieve the node.
ExplodedNodeImpl* Node = WU.getNode();
// Dispatch on the location type.
@@ -138,6 +146,12 @@
void GREngineImpl::HandleBlockEntrance(const BlockEntrance& L,
ExplodedNodeImpl* Pred) {
+ // Increment the block counter.
+ GRBlockCounter Counter = WList->getBlockCounter();
+ Counter = BCounterFactory.IncrementCount(Counter, L.getBlock()->getBlockID());
+ WList->setBlockCounter(Counter);
+
+ // Process the entrance of the block.
if (Stmt* S = L.getFirstStmt()) {
GRStmtNodeBuilderImpl Builder(L.getBlock(), 0, Pred, this);
ProcessStmt(S, Builder);
@@ -196,7 +210,7 @@
ExplodedNodeImpl* Pred) {
assert (B->succ_size() == 2);
- GRBranchNodeBuilderImpl Builder(B, *(B->succ_begin()), *(B->succ_begin()+1),
+ GRBranchNodeBuilderImpl Builder(B, *(B->succ_begin()), *(B->succ_begin()+1),
Pred, this);
ProcessBranch(Cond, Term, Builder);
@@ -244,7 +258,7 @@
}
// Only add 'Node' to the worklist if it was freshly generated.
- if (IsNew) WList->Enqueue(GRWorkListUnit(Node));
+ if (IsNew) WList->Enqueue(Node);
}
GRStmtNodeBuilderImpl::GRStmtNodeBuilderImpl(CFGBlock* b, unsigned idx,
@@ -325,5 +339,5 @@
if (!GeneratedFalse) generateNodeImpl(Pred->State, false);
for (DeferredTy::iterator I=Deferred.begin(), E=Deferred.end(); I!=E; ++I)
- if (!(*I)->isSink()) Eng.WList->Enqueue(GRWorkListUnit(*I));
+ if (!(*I)->isSink()) Eng.WList->Enqueue(*I);
}